Abstract
This systematic review aimed to summarize the effects of astaxanthin (ASX) supplementation on oxidative stress, inflammation, and metabolic regulation in human studies. A systematic search was conducted in Scopus, Web of Science (WOS), and PubMed for articles published between 2020 and 2025. Fifteen studies involving human participants were included, while in vitro and animal studies were excluded. ASX consistently reduced pro-inflammatory cytokines (IL-6, TNF-α, TGF-β1) and oxidative stress indices while increasing antioxidant capacity (SOD, TAC). Combined ASX and exercise interventions improved body composition, lipid profiles, insulin sensitivity, and immune recovery. In women with Polycystic Ovary Syndrome (PCOS) or endometriosis, ASX downregulated endoplasmic reticulum stress-related apoptotic pathways and improved oocyte and embryo quality. Cardiometabolic and respiratory outcomes showed improved endothelial function and reduced disease severity. Astaxanthin demonstrates broad antioxidant and anti-inflammatory properties, supporting its role as a promising adjunctive therapy for metabolic, reproductive, and cardiovascular health. Further well-designed clinical trials are needed to confirm optimal dosing and mechanisms of action.